Breeding practices - a personal experience

 

When I bought my first devon rex I knew very little about breeding.

I actually was not even thinking about breeding... until that amazing creature came to live with me. I immediately fell in love and wished I could raise a litter... or two... or well... maybe more? :-)


I started collecting information from the breeders I were in touch with, to better understand what breeding meant and to also realize if I had enough time and resources to raise a litter in the proper way.

The first information I got were quite scary. Apparently Devon Rex kittens are tiny delicate creatures and the most critical moments are at birth and the next few weeks of life. The average weight of a devon kitten is between 60 and 75 grams and when it happens a kitten is less than 60 grams (something that happens almost in every litter)... there’s not much to do to save the little one. A 20% average mortality completed the picture.

It was quite scary, but you know what kind of magic a devon rex is capable of doing. I was really getting into it and was already dreaming (literally, at night!) of my first kittens.

I started looking for a queen who was related to my boy, as apparently it was a good way to get a better type in the kittens.


As a natural consequence I started to look for reading material that could help me understand a bunch of things in a better way.

When I was in college I was very passionate about genetics (and volcanoes as well... just to share!) so that I was on cloud nine when I realized there was a genetics book made just for breeders. I bought it right away and read all of it in just a couple of weeks. That is when I became a "cat genetics freak". There's nothing I can say in my defense! It happened 13 years ago and it never changed.


Robinson's genetics book for cat breeders and veterinarians taught me a lot. It explained to me the different breeding practices, their pros and cons, the genetics of colors, of mutations, some genetics of the populations applied to cats, fertility issues and more.

After this enlightening reading I already had plans!
As a start I checked the total inbreeding percentage of my devon boy and I was kind of shocked. He had a 44.5% of inbreeding. Not as simple as it seems... it's just a number... a number that can be achieved in many different ways. In the case of my boy it was achieved with a continuous inbreeding, done several times, generation after generation.

Inbreeding after inbreeding with some line-breeding too. According to Robinson's the inbreeding depression can express itself in many different ways, such as a decrease in the litter size and weights, an increase in weakness and kittens mortality and a general weakness of the immune system. I surely didn’t want to add more inbreeding to that pedigree and decided to look for a queen with a different line - but good type - to decrease the total amount of inbreeding and have better chances of healthy kittens.


I still didn’t know what it meant in practice... but I got a much better idea when my kittens were born. My queen had a litter of 6 and none of them were below the 72 grams.

The biggest kitten was 96 grams, the “tiniest” 72... and they were 6! They were all strong and healthy and grew up as fat as possible.


I certainly know that there are a number of issues that can happen in young kittens, and I also lost a few kittens in my several years of breeding. It happened rarely and the mortality rate of my cattery is assessed at below 10% (as little as 5% if you don’t consider the kittens born already dead), with no change in percentages if you take into account the life expectation of my cats as adults.

I’m persuaded that a huge part of this result is due to my continuous efforts in improving my cats diversity and my determination in making sure health is always my main goal.


My main breeding tool is outcrossing.

Many think that the word “outcrossing” is referred to breedings between different breeds, but in Robinsons it refers to the practice of breeding 2 cats of the same breed, but different lines. The breeding practice put in place is basically to mate cats quite close to the standard but coming from different lines.

Of course in the devon rex breed this can be done in a limited way due to the lack of lines or due to the necessity to stay away from lines with known health issues. Also it is not so uncommon to find the same cats when you go back in the pedigree and check after the 5 common generations.

Even so it’s a method that can be successfully applied to breeding. It leads to some amazing cats and some pet quality ones, but all having in common a high diversity and a good to strong immune system.


I do use cats who have inbreeding and/or linebreeding in their pedigrees. I always buy cats with a very good type and want to achieve an extreme look in my cats. I love the CFA extreme look and don’t settle for less.

But I found a breeding method that works good for me and with which I’m sure my kittens and cats won’t suffer from inbreeding depression or suddenly start to die from a common disease they should be able to defeat.


I don’t do inbreeding, ever. It freaks me out to think that one single breeding will weaken the kittens immune system by 50% or 25%, drastically decrease their chances to fight common diseases and possibly affect their life expectation.

I do use linebreeding though, even if not so often. I think it can be useful at times, and if used in a wise way it helps to select extreme cats. My experience with outcrossing has taught me that inbreeding is not the only way to achieve extreme type. It’s for sure the only way to have a whole litter of amazing kittens, but at what cost?


Outcrossing will make breeding more challenging, no doubt about it, but it will also guarantee a future to this beautiful breed of cats.